[Elecraft] Questions on the KRC2 - part 1

[Jack Brindle]

Apparently the reflector doesn't like messages over a certain size, so 
my reply to Bruce was rejected. He has already seen the response, but I 
thought the rest of you folks would like to see it also. So, here it is 
in several parts...

Great questions!  With the upgrade capability of the box, many of its 
features will be changing or added to as time progresses. exactly what 
gets added will come from user's suggestions and ways of doing things 
we haven't anticipated. That's the cool thing about the box - because 
it is configurable, you get to decide what it really does!

On Friday, May 30, 2003, at 12:33  PM, Bruce Thompson wrote:

> 1.  Does it have a power switch?  Running power in my vehicle is always
> a pain.

No. There are three power feeds to the KRC2, for feeding two separate 
areas. Main controller power can either come directly from the KRC2 or 
the barrel connector. In either case, the voltage must be limited to 
less than 15 volts (same as K2). Current drain is no more than about 20 
mA on the units I have tested with LED on full. Turn the LED off, and 
current drops.

The second power feed is for powering the source relay drivers. This 
may come from the barrel connector, with its 15V max rating, OR from a 
terminal pin, allowing  a much higher voltage, up to 50 volts. Max 
current drain is about 1 amp on this circuit, limited by the terminal 
connector and the heat dissipation of the driver chips.

> 2.  How much current does it draw?  Is it something that could just be
> left on all the time?  Does it have a sleep mode?

See above for current requirements. It does not have a sleep mode at 
this time.

> 3.  Can it detect when the K2 is turned off or on and then do something
> such as switch on one of the transistors?  (I'm assuming here that the
> unit wouldn't actually detect the loss of power but the loss of
> communication with the K2).

There are two ways of looking at this. If it is powered from the K2, 
then it certainly detects when the K2 powers up. Power-up of the KRC2 
is an event that may cause some user-programmed action. Of course in 
this scenario when the k2 is powered off, the KRC2 will immediately 
lose power, and won't be able to perform any action. it will dim the 
LED, however. ;-)

The second case is powering the KRC2 from the barrel connector. In this 
mode we have the ability to sense inputs from the K2, but do not 
currently do so to provide a "K2-on" event/action. It is an interesting 
idea, however. When the K2 is turned on, we get a flurry of information 
from the unit such as band and ACC settings. When the KRC2 powers up, 
it automatically sets its relay outputs to off, so the KRC2 uses the 
K2's power-on communications to set the relay outputs. If you are 
requesting a "K2-on" event, i will definitely consider it. It could 
resolve some interesting situations that may occur from the K2 being 
turned off, then back on...

> 4.  Can the PC serial port also be an output?  I wouldn't mind
> programming it to control other serial devices.

Yes, but that is reserved for upgrade mode at this point. Serial port 
messages come in from the K2, cause something to happen in the KRC2, 
then a result may be sent back out. It is quite possible to send out a 
command in response to a local event (such as a key press) to have the 
K2 do something. If the upgrade switch is in the"UPG" position, that 
data would go out the PC port. Note, however, that the data must be in 
standard K2 communications format as described by the KIO2 reference 
manual. If you want to send some text, it would need to be part of a KY 
command, of the sort: "KY THIS IS A TEXT MESSAGE;" and would be subject 
to the normal limitations of the command (24 chars maximum). The KRC2 
does not impose the character maximum, however, so you could send more, 
subject to the overall limitation of size of the operand area (I'll 
have to explain this later).

> 5.  It looks like there is an LED on the front.  Can it be programmed?

Not at present. What would you like it to do? It has the ability to 
have four levels (off to full on), and certainly could be placed under 
user control. Do I hear a suggestion here?

> 6.  Can the unit write something to the display of the K2?  (Useful on 
> a
> button press or some automatic function)

Only for displaying ACCessory text. (See the K2/KIO2 ACCessory 
command). This is VERY limited. The K2 simply doesn't have the ability 
for accessories to send in text which can be displayed on the LCD. 
Maybe someday, but that isn't under my control...

> 7.  Can it detect when the "tune" button has been pressed?  I'd like to
> use that to turn off the amp automatically.

I have not found a way to do this yet. There simply is no indication 
that I have found from the K2 that the transmitter is in TUNE mode. It 
_does_ know when the radio is in transmit mode, and does not allow 
relay switching during this time.

> 8.  How many outputs are available?  Can't quite read the PC board in
> the photograph.

Sixteen. All with separate source and sink capabilities. They can be 
diode ORed if needed (say for a triband beam), but we are also going to 
allow the user to configure the driver map so that a single output may 
be turned on for several bands so you don't have to use diodes. This 
will probably allow you to use the drivers from other triggers besides 
the bands.

The legends you are trying to read indicate the ten HF bands (including 
60m), three transverter outputs, and three ACCessory outputs. The 
transverter and ACC outputs may be mapped either fully decoded (1 of 3) 
or binary non-decoded output. This means you could have a maximum of 
eight ACCessory outputs if you'd like. The K2 will support that many 
devices on its ACC menu; I have tested it... The text displayed for the 
ACC menu is stored in the KRC2 and sent to the K2 on command. It is 
also configurable by the user. Also, you can set the ACC outputs 
separately from the K2. for example, the demo version has buttons that 
turn each ACC output on depending on which button is pressed, or all 
off if a fourth button is pressed.


-Jack Brindle, WA4FIB
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